[XS] Change in coreboot[main]: mb/asus/p8z77-m: Revert SIO IRQ settings carried from OEM

[Keith Hui (Code Review)]

Attention is currently required from: Fabian Groffen, Keith Hui, Paul Menzel.

Keith Hui has uploaded a new patch set (#10) to the change originally created by Fabian Groffen. ( https://review.coreboot.org/c/coreboot/+/75137?usp=email )

Change subject: mb/asus/p8z77-m: Revert SIO IRQ settings carried from OEM
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mb/asus/p8z77-m: Revert SIO IRQ settings carried from OEM

Revert super I/O IRQ polarity settings replicated from OEM firmware
back to its power-on defaults.

With OEM settings COM 1/UART A/serial port 1 gets blocked right after
the kernel boots.  It no longer works or responds, which actually means
the Linux boot process gets stuck forever when configured to write
to ttyS0.

Also revised the comment on another SIO setting to say it's being set
for PECI.

TEST=Not using these settings, I have not found any downside.
Serial keeps working, sensors still work, S3 suspend/resume works
correctly.

Reported by Fabian and confirmed Keith.

Signed-off-by: Fabian Groffen 
Signed-off-by: Keith Hui 
Change-Id: Iae526762e79e9e2d46d06e12c338f375e5555e8c
---
M src/mainboard/asus/p8x7x-series/variants/p8z77-m/overridetree.cb
1 file changed, 1 insertion(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/37/75137/10